36.9k views
4 votes
Points A(-2, 4), B(1, 3), C(4, -1) and D form a parallelogram. What are the coordinates of D?

(5, 5)



(0, 0)



(1, -2)



(1, 0)



(3, 4)

2 Answers

4 votes
After some work I concluded that the coordinates to D are (-2,0) 
User Abdessamad Doughri
by
6.7k points
4 votes

Answer: The coordinates of D are (1,0).

Explanation:

Given : The vertices of parallelogram are A(-2, 4), B(1, 3), C(4, -1) and D.

Let the fourth vertex be D(x,y).

We know that the diagonal of parallelogram bisects each other.

i.e. Mid points of AC = Mid point of BD [ where AC and BD are diagonals of parallelogram ]

i.e.


((-2+4)/(2),(4-1)/(2))=((1+x)/(2),(3+y)/(2))\\\\\Rightarrow\ (1,(3)/(2))=((1+x)/(2),(3+y)/(2))\\\\\Rightarrow\ (1+x)/(2)=1\ \ \ \ , \ (3+y)/(2)=(3)/(2)\\\\\Rightarrow\ 1+x=2\ ,\ \ \ 3+y=3\\\\\Rightarropw\ x=1\ \ ,\ \ y=0

Hence, the coordinates of D are (1,0).

User Knowband Plugins
by
7.5k points
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